Process of working up ethyl cellulose into homogeneous plastic masses



Patented June 13, 1933 UNITED STATES EDUARD Donn AND o'rro LEUGHS, or

ELBEBFELLD, AND LEO RGSENTHAL, OF

. VOHWINKEL, NEAR ELBERFELD, GERMANY, ASSIGNORS 'IO FARIBENINDUSTRIE AKTIENGESELLSCHAIT, F.FRANKFORT-ON-THE-MAIN, GERMANY, A CORPORATION onennmjAnY rnocnss on WORKING 13']? man onmuLosn nvro nomoennnous rLAsTIo MASSES No Drawin Application filed lltay 1929, Serial no. 364,690, and in Germany March 31, 1927.

The present invention relates toa process of working up ethyl cellulose into homogeneous plastic masses, more particularly it relates to a process of preparing homogeneous plastic masses from ethyl cellulose with an ethoXy content of 42-48%.

According tothe present invention, ethyl cellulose with an ethoXy content of about 4248% is worked up into homogeneous plastic masses by means of an organic solvent which dissolves thecellulose other when hot, but which does not dissolve said cellulose ether in the cold. In carrying out our process the ethyl cellulose is dissolved in the hot solvent as mentioned above, if desired,

the solution may be filtered, for example through a filter cloth, and then the SOllltlOIl Sis cooled, whereby the ethyl cellulosesep-arates. This separation generally is finished 20 when the solutionhas reached a temperature of about20 C. The ethyl cellulose which has beenseparated is filtered and, while it still contains some of the solvent, is worked up into a homogeneous plastic mass by removing the solvent in the usual manner, for example, mechanically or with theapplication of heat as for instance by treating the mass on heated rollers, if desired in vacuo. The process is advantageously carriedout by preparing highly concentrated solutions of the eth 1 cellulose, say by dissolving about 1 part 0 the ethyl cellulose in 1 to 4 parts of the solvent at a temperature of about 80 C. or more and if necessary, mechanically promotingthe process of dissolving of the ethyl cellulose, for example by kneading." 0n

coolin ,the ethyl cellulose separates and solidi es to form a more or less jelly-like mass from which the solvent is removed in. the usual manner,say by rolling and heating. If desired, there may be added to the solution of the ethyl cellulose organic or inorganic coloring matters, or inert fillers such as talcumo-r saw-dust or plastifying agents such as camphor, tricresylphosphate and the like. r y

Suitable solvents for the-purpose of our invention are benzene, aliphatic and hydroaromatic hydrocarbons, having a boiling point of about at least 80 0., such as ligroin,

liydrotoluene, cyclohe xane or niXtures of 1 these hydrocarbons, for example mixtures of hydroaromatic hydrocarbons known by the trade-names Bornylan and Sangajol, said mixtures being obtained from Borneo earth 011 and havlng a bo1l1ng point from 130- 154 C. and 160-170 C. respectively.

The specific solvent to be used for the purpose of the invention depends on the ethoxy j specific mixture used isadapt-ed to the ethyl cellulose to be purified, that is, the higher the ethoxy content is the higher must be the ratio of the aliphatic or hydroaroniatic hydrocarbon in the mixtures used of course mixtures of The invention is illustrated by the follow ing examples, but is not restricted thereto:

y Example] f 2 kg's. of ethyl cellulose containing 46% of ethoxy groups are dissolved in "40 kgs. of ligroin, (boiling point 110 C.) or in Bornylan at C. the solution is filtered hot, if necessary, through a filter press and then cooled to room temperature in a stirring vessel with thorough stirring. The ethyl cellulose precipitates as a fine flaky product. It is isolated and treated on heated rollersof (50 C. until the greater part of the solvent has been remeved. On cooling the mass 1 yields a hard, tough and elastic material. 1

l Ewamplc 2 25 parts by weightof ethyl cellulose with an ethoxy content of 47% and 7 5 parts by weight offbornylan, having a boiling pointof about Glare workedup to a homogeneous paste in a kneading apparatus at 80-90. C. The material, which is plastic at ion further worked up into articles of manufacture in the known manner.

Example 3 2 kgs. of ethyl cellulose having an ethoxy content 01 44% are dissolved at 8090 0. in 4 kgs. of a mixture consisting of 1 part benzene and 1 part of bornylan and the solution is cooled to 30 0; A transparent gelatinlike mass precipitates. The mass is rolled with rollers into plates at about 0. and rolling is continued until the greater part of the solvent has been removed. On cooling ahard, tough and elastic material is obtained.

This is a continuation in part of our application Ser. No. 260,240, filed March 8, 1928.

WVe claim 1. A process of preparing homogeneous plastic masses from ethyl cellulose which process comprises dissolving ethyl cellulose with an ethoxy content of 42 to 48% at about 0. in an organic solvent which dissolves the ethyl cellulose only when hot of the group consisting of benzene-aliphaticand hydroarom'atic-hydrocarbons having a boiling point of at least about 80 0., precipitating the ethyl cellulose by cooling the solution at least to 30 0., filtering and working up the precipitate formed, while still containing some of the solvent, into plastic masses.

2. A process of preparing homogeneous plastic masses from ethyl cellulose which process comprises dissolving ethyl cellulose with an ethoXy content of 42 to 48% at about 80 0. in an organic solvent which dissolves the ethyl cellulose only when hot'of the group consisting, of benzene-ali'phaticand hydroaromatic-hydrocarbons having a boiling point of at least 80 0., precipitating the ethyl cellulose bycooling the solution at least to 30 0., filtering and mechanically removing the solvent from the precipitate formed.

3. A process of preparing homogeneous plastic masses from ethyl cellulose which process comprises dissolving ethyl cellulose with an ethoxy content of 42 to 48% at about 80 0. in an organic solvent which dissolves the ethyl cellulose only when hot of the group consisting of benzene-aliphatio and hydroaromatic-hydrocarbons having a boiling point of at least 80 0., precipitating the ethyl cellulose by cooling the solution at least to 30 0., filtering and mechanically removing the solvent from the precipitate formed with the application of heat.

'4. A process of preparing homogeneous plastic masses from ethyl cellulose which process comprises dissolving ethyl cellulose with an ethoXy content of 42 to 48% at about 80 in ligroin, precipitating the ethyl cellulose by cooling the solution at least to 30 0., filtering and working up the precipitate formed, while still containing some of the solvent, into plastic masses.

5. A' process of preparing homogeneous plastic masses from ethyl cellulose which process comprises dissolving one part by Weight of ethyl cellulose with an ethoXy content of 46% in 20 parts by weight of ligroin, having aboiling point of 110 0., at about 80 0., precipitating the ethyl cellulose, while stirring, by cooling the solu tion to about 20 0., filtering and removing the solvent iromthe fine flakes formed by treating the product on rollers at'60 0.

A process of preparing homogeneous plastic masses from ethyl cellulose which process comprises dissolving ethyl cellulose with an ethoXy content of 42 to 48% at about 80 0. in a mixture of hydrocarbons boiling from 130 to 154 0. and being obtained by fractionating Borneo earth oil, precipitating the ethyl cellulose cooling the solution at least to 30 0., filtering and working up the precipitate formed, while still containing some of the solvent, into plastic masses.

7. process of preparing homogeneous plast c masses from ethyl cellulose which process comprises dissolving one part. by we ght of ethyl cellulose with an ethoXy content of 46% in 20parts by weight of a mixture of hydrocarbons boiling from 130, to 154 0. and being obtained by iractionating Borneo earth oil at about 80 0., precipitatingthe ethyl cellulose, while stirring, by cooling, the solution to about 20 0., filtering and removing the solvent from thefine flakes gggned by treating the product on rollers at v process of preparing homogeneous plast c masses from ethyl cellulose which process comprisesv dissolving ethyl cellulose with an ethoxy' content of 42 to 48% at about 80. in a mixture consisting of one part of benzene and one part of a mixture othydrocarbonsboiling from130to 154 0. and be ng. obtained by fractionating Borneo earth, o l, precipitating the ethyl cellulose by cooling the solution at least to 30 0., filtering and working up the precipitate formed, while still containingv some of the solvent into plastic masses.

9, A process of preparing homogeneous plastic .masses from ethyl cellulose which process comprises dissolving one part by weight of ethyl cellulose with an ethoxy content 'of 44% in'2 0 parts by weight of mixture of benzene and a mixture of hydrocarbons boilingfrom 130 to 154 0. and bein obtainedby fractionating Borneo earth oil at about 80 0., precipitating the ethyl cel lulose, while stirring, by cooling the solutionto 30 0., and filtering and removin the solvent from the gelatinous mass formed igs In testimony whereof, We 'hereuhto set our hands and afiix our seals.

EDUARD DGRR OTTO LEUCHS. LEO ROSENTHAL.

[1,. s.] [L. s.] [L. 5.] 

